ArtifactSpec a = createArtifactSpec("a", "1.0");
        ArtifactSpec b = createArtifactSpec("b", "1.0", nearestScope);
        ArtifactSpec c = createArtifactSpec("c", "1.0");
        a.addDependency(c);
        ArtifactSpec dNearest = createArtifactSpec("d", "2.0");
        b.addDependency(dNearest);
        ArtifactSpec dFarthest = createArtifactSpec("d", "3.0", farthestScope);